385 



THE AQUARIUM. 



THERE arc few things that throw a clearer light upon animal and 

 vegetable life than an aquarium, whether it be filled with sea water 

 or fresh water. Men, in a confined space, where there is not a 

 sufficiency of fresh air, die through suffocation ; water- animals, 

 whether covered with shells or scales, also soon perish in a limited 

 supply of water, both man and fish being destroyed through the 

 excess of carbonic acid gas which they throw out, and by which they 

 are poisoned. But this never occurs save through age, decay, or 

 disease while there is a sufficiency of oxygen to inhale, as what we 

 draw in overpowers and renders harmless the poison we throw out, 

 which can be proved at any moment by shutting ourselves up in a 

 confined space where there is but little air, and remaining there 

 until we find it difficult to breathe ; then letting in a current of fresh 

 air, when we once more breathe freely. We will confine ourselves to 

 the word fishes, whether we speak of a shrimp or a shark, a whelk 

 or a whale though, by the way, a whale is not a fish at all, us it 

 brings forth its young alive, and suckles them as a. cow does a calf; 

 but no matter, all our aquatic animals which are kept in an aquarium 

 are understood to be fishes. Now, fishes can no more live long in an 

 aquarium, in sea or fresh w r ater only, than you could in an empty 

 water-butt that was bunged, pitched, and made airtight; the car- 

 bonic gas you throw from your body would destroy you in no time, 

 while if the bung was taken out and fresh air let in you might live 

 there as long as your friends liked to keep you, though it would be a 

 great relief at times to apply your mouth to the bung-hole and have 

 a good mouthful of fresh air. But there are no end of sea-weeds 

 call them marine algas if you like that take in this poisonous car- 

 bonic acid gas, and give out immense quantities of oxygen, as you 

 may see by the thousands of bright silvery bubbles with which these 

 sea-weeds are covered, and which they are ever sending to the 

 surface like fairy balloons, from their sea-green garden-grounds 

 the fishes the happy spectators. This is the life of the water, anu 

 alone enables the fishes to "live, and move, and have a being;" 

 without their sea-weeds they would be as dead as the old Egyptian.* 

 who built the pyramids. Sometimes this oxygen will be poured out 

 in such quantities when the sun shines too powerfully on the aqua- 

 rium as to lift the sea- weeds from their moorings, like so many blown 

 bladders, when, all spangled with silver stars, they will float, on the 

 surface, until, ceasing to be acted upon so powerfully by tjie light, 

 the weeds will again drop down into their sea-green beds; and these 

 sea-weeds, that throw out so much oxygen, and form, so to speak, 

 the blood of fishes, sometimes spread over hundreds of miles of ocean, 

 like those found in the Atlantic, that cover such an immensity of 



